{"operation":"document","citation":"04-0023","title":"Haas TCM — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2004-05-05","effective_on":null,"summary":"04-0023 response to Haas TCM concerning 173.27.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-04-0023.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-04-0023.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-04-0023","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2004/040023.pdf","body":"<<<PAGE 1>>>\n\nIS.Departmen\nf Transportation\n00 Seventh Street, S.V\nlashington, D.C. 2059\nSpecial Programs\nResearch and\nMAY 5 2004\nAdministration\nMr. Larry Holcombe\nHaas TCM\nAccount Manager\nRef. No.: 04-0023\n1646 West Chester Pike\nWest Chester, PA 19382\nDear Mr. Holcombe:\nThis responds to your letter concerning determination of the vapor pressure to calculate the test\npressure for packages intended for air transportation in § 173.27 of the Hazardous Materials\nbelow:\nRegulations (HMR; 49 CFR Parts 171-180). Your questions are paraphrased and answered\nQ1. Is it correct to obtain the vapor pressure from engineering tables if the liquid consists of a\nsingle chemical component?\nAl. Yes, obtaining the vapor pressure for a liquid that consists of a single chemical component\nfrom engineering tables is acceptable.\nQ2. For liquids with multiple chemical components, you propose to use vapor pressure from\npressure threshold limit equal to 50% of minimum test pressure for the package. If the vapor\nengineering tables for the most volatile component at the specified temperature and set a vapor\npressure of the mixture exceeds the threshold limit, you further propose to measure the vapor\npressure by laboratory testing. You ask if this approach is suitable.\nA2. We are unable to determine the suitability of your approach. The Hazardous Materials\nRegulations do not prescribe specific methods for determining the vapor pressure. The vapor\ndesi may bad the packa by ising or of viticstanding the pressure regattements in 8 17327\nwithout leakage may be used.\nI hope this determination is helpful.\nSincerely,\nHithe a mitthel\nHattie L. Mitchell\nChief, Regulatory Review and Reinvention\nOffice of Hazardous Materials Standards\n173.27\n040023\n\n<<<PAGE 2>>>\n\nHaas TCM\n1646 West Chester Pike\nhaas\nWest Chester, PA 19382\nPhone:\n(610) 436-9840\nFax:\n(610) 436-9076\n(800) 220-4227\nwww.haascorp.com\nCorbin\nJanuary 23, 2004\n§173.27\nFrits Wybenga\nAir\nU.S. Department of Transportation\nDeputy Associate Administrator\n04-0023\nDHM-1\n400 7th St., S.W.\nWashington, DC 20590-0001\n202-366-0656\nRE: 49 CFR 173.27 General requirements for transportation by aircraft\nDear Deputy Wybenga:\nPart 173.27 of 49 Code of Federal Regulations requires that shippers ensure that containers of\nregulations include using the vapor pressure of the liquid at specified temperatures (50 or 55\nregulated liquids do not leak under conditions of air shipment. The methods stated in the\ndegrees Celsius) to determine container pressure capacities.\nobtaining the needed vapor pressure data.\nWe request your Department's advice on the suitability of our proposed approach, below, for\n1. Where the liquid consists of a single chemical component we propose to use engineering\ntables to obtain the vapor pressure of the component at the specified temperatures.\n2. Where the liquid consists of multiple chemical components we propose to select the most\nvolatile component and use engineering tables to obtain the vapor pressure of that\nSince the regulations specify a minimum packaging capacity (14 psig or 11 psi\nepending on the liquid, 49 CFR 173.27 c) 2) i)), we propose to set a threshol\npackaging requiremessure estimates equal to 50% of the minimum value for\nb. Any engineering estimate of a mixture that exceeds the threshold limit vapor\nvapor pressure.\npressure will automatically be set aside for laboratory testing to measure the\n3. We propose to run a pilot program to test the suitability of this approach. A sub-sample\nof the liquids where engineering estimates are made (per steps 1. and 2. above), and\nThe vapor pressure determined by the two methods, i.e., engineering estimate and lab\nwhich were below the threshold limit will also be tested in the lab for the vapor pressure.\ntest, will be used to calculate the required packaging\n\n<<<PAGE 3>>>\n\nFrits Wybenga\nJanuary 23, 2004\nPage 2\n4. This approach of using a combination of engineering estimates and lab testing will be\n100% on the packaging requirements.\nconsidered suitable if the pilot shows that both engineering estimates and lab tests agree\nThank you.\nSincerely,\nImme Fund for\nLarry Holcombe\nHaas TCM\nAccount Manager","truncated":false,"body_characters":4143}